The present invention relates generally to apparatus for cleaning heat exchanger tubes and, more particularly, to apparatus for cleaning heat exchanger tubes wherein each tube has a chamber at each of its opposite ends for capturing a tube cleaning element, such as a brush and a sponge ball. Such a tube cleaning element is adapted for movement in opposite directions through the tube upon reversing the direction of flow of heat exchange fluid therethrough by means of a valve arranged in a fluid inlet or outlet of the heat exchanger, so that the inner surface of the tube is cleaned by the moving tube cleaning element.
In conventional heat exchangers, spaced opposed front and rear enclosures are formed by partition plates for receiving heat exchange fluid. A bundle of heat exchange tubes whose ends are mounted to the partition plates fluidly extend between and communicate with the two enclosures. The chamber for capturing a cleaning element, such as a brush, is attached to each end of each exchanger tube and extends into the heat exchange fluid enclosure from the respective end of the heat exchanger tube. The cleaning element moves back and forth through the tube upon reversing the flow of heat exchange fluid so that the inner wall of the tube can be cleaned by the moving cleaning element.
The chamber for capturing the tube cleaning element is conventionally secured to a respective end of a heat exchange tube by means such as expanding the chamber within the tube end to tightly engage the same, by adhesive, or the like. For example, in one arrangement, a groove is formed around the inner surface of the end of a heat exchange tube in which an end of the chamber for capturing the cleaning element is inserted and then expanded to thereby tightly engage the end of the tube. On the other hand, the chamber for capturing the cleaning element is provided at its free end with a detachable stop member formed of an elastic material or the like which enables the cleaning element to be removed from the chamber.
Conventional arrangements by which chambers are secured to the ends of respective heat exchange tubes present problems in connection with the replacement of the cleaning elements when necessary due to wear or damage. In the arrangement described above, where the chamber is provided with a detachable stop member, although it is possible to easily remove the cleaning element for maintenance, since the chamber is mounted to the heat exchanger tube through an expansion of one of the members or through adhesion, significant amounts of labor and time are required in assembly, especially in heat exchangers which include a large number of heat exchanger tubes. Further, mounting of the chambers to the heat exchanger tubes through the enlargement of the chambers or tubes or through adhesion are not very reliable and the heat exchange tubes or chambers often crack due to excessive stresses created during expansion. Moreover it is possible for the chambers to become disengaged from the respective heat exchanger tubes due to insufficient engagement force so that they do not reliably engage the grooves formed around the inner surface of the tube ends.